Power supply circuits and methods for supplying stable power to control circuitry in an electronic ballast

Abstract

Electronic ballast power supply/control circuits and methods that can be used to supply starting power to PFC control chips and that can be used to control ballasts so that PFC and inverter power supply circuits supply stable power to control circuitry even when the ballasts are performing advanced ballast functions. The circuits and methods supply starting power more quickly and efficiently than prior art starting circuits and control ballasts by either loading PFC circuits or inverter circuits included in the ballasts. The circuits load PFC circuits by connecting load resistors to the PFC circuits or by operating the inverter circuits at high frequencies that generate switching losses in the inverter transistors that load the PFC circuits. Inverter circuits are loaded by operating the inverter at frequencies that are much higher than preheating, igniting, and normal operating frequencies.